Two species of Pratylenchoides recovered from the grasslands in Sabalan region and one species recovered from natural habitats of Tehran are illustrated based on morphological, morphometric and molecular characters. The first species, P. crenicauda is characterized mainly by its lip region with three-four annuli, lateral field with four incisures areolated throughout the length and having rod shaped sperm cells. It is further distinguished by the positions of the pharyngeal glands nuclei. P.

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... nicauda was found in Tehran and its morphological characters and phylogenetic relations with other species are discussed. The Iranian populations of P. variabilis are characterized by three lip annuli, stylet 20-22 µm long, four and six incisures in lateral field, rounded sperm and one of the pharyngeal glands nuclei located posterior to pharyngo-intestinal valve. The phylogenetic tree inferred from the partial sequences of D2-D3 segment of 28S rDNA revealed the three sequenced species are separate from each other and form a clade with high (1.00) Bayesian posterior probability (BPP) in Bayesian inference (BI) and 86% bootstrap support value (BS) in maximum likelihood (ML) analyses with other two sequenced species of the genus for this genomic region.